Dual spray chamber

ABSTRACT

A dual spray chamber apparatus is described. In one or more implementations, the dual spray chamber apparatus includes a first cyclonic spray chamber for receiving an aerosol and conditioning the aerosol to separate a first conditioned portion of the aerosol from a second portion of the aerosol. The first cyclonic spray chamber defines a first chamber interior and comprises an input port in fluid communication with the first chamber interior. The dual spray chamber apparatus also includes a second spray chamber coupled with the first cyclonic spray chamber for receiving the first conditioned portion of the aerosol and further conditioning the first conditioned portion of the aerosol. The second spray chamber defines a second chamber interior and comprises an output port for expelling a first further conditioned portion of the first conditioned portion of the aerosol from the second chamber interior.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of 35 U.S.C. §119(e) of U.S.Provisional Application Ser. No. 61/593,405, filed Feb. 1, 2012, andtitled “DUAL SPRAY CHAMBER.” The present application is also acontinuation-in-part under 35 U.S.C. §120 of U.S. patent applicationSer. No. 13/238,237, filed Sep. 21, 2011, and titled “DUAL-CYCLONICSPRAY CHAMBER,” which claims the benefit of 35 U.S.C. §119(e) of U.S.Provisional Application Ser. No. 61/385,012, filed Sep. 21, 2010, andtitled “DUAL-CYCLONIC SPRAY CHAMBER APPARATUS.” U.S. ProvisionalApplication Ser. Nos. 61/385,012 and 61/593,405, and U.S. patentapplication Ser. No. 13/238,237 are herein incorporated by reference intheir entireties.

BACKGROUND

Analytical equipment, including Mass Spectrometers (MS) and AtomicEmission Spectrometers (AES), are utilized for detecting trace elementsof species in samples. Inductively Coupled Plasma MS (ICP-MS) andInductively Coupled Plasma AES (ICP-AES), which may also be referred toas ICP Optical Emission Spectrometry (ICP-OES), are two sample analysissystems used by laboratories for the determination of trace elementconcentrations and isotope ratios in liquid samples. ICP spectrometryemploys electromagnetically generated partially ionized plasma, whichcan reach temperatures of approximately seven thousand Kelvin (7,000 K).When a sample is introduced to the plasma, the high temperature causessample atoms to become ionized or emit light. Since each chemicalelement and ratios thereof produces a characteristic mass or emissionspectrum, measuring the spectra of the emitted mass or light allows forthe determination of the elemental composition of the original sample.

SUMMARY

A dual spray chamber apparatus is described. In one or moreimplementations, the dual spray chamber apparatus includes a firstcyclonic spray chamber for receiving an aerosol and conditioning theaerosol to separate a first conditioned portion of the aerosol from asecond portion of the aerosol. The first cyclonic spray chamber definesa first chamber interior and comprises an input port in fluidcommunication with the first chamber interior for receiving the aerosolto be conditioned by the first cyclonic spray chamber. The firstcyclonic spray chamber may include a baffle. The dual spray chamberapparatus also includes a second spray chamber coupled with the firstcyclonic spray chamber for receiving the first conditioned portion ofthe aerosol and further conditioning the first conditioned portion ofthe aerosol to separate a first further conditioned portion of the firstconditioned portion of the aerosol from a second conditioned portion ofthe first conditioned portion of the aerosol. The second spray chamberdefines a second chamber interior and comprises an output port forexpelling the first further conditioned portion of the first conditionedportion of the aerosol from the second chamber interior. The secondspray chamber may be a cyclonic spray chamber.

The dual spray chamber apparatus may further include a drain port influid communication with the first chamber interior for removing thesecond portion of the aerosol from the first cyclonic spray chamber. Thedual spray chamber apparatus may also include a baffle at leastpartially disposed within the second chamber interior, where the baffledefines an interior portion for receiving the first further conditionedportion of the first conditioned portion of the aerosol. The dual spraychamber apparatus may further include a linking chamber for coupling thefirst cyclonic spray chamber to the second spray chamber. The linkingchamber may comprise a taper and may form an annular drain portion forremoving the second conditioned portion of the first conditioned portionof the aerosol from the second spray chamber. The volume defined by thefirst chamber interior may be greater than the volume defined by thesecond chamber interior.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

DRAWINGS

The Detailed Description is described with reference to the accompanyingfigures. The use of the same reference numbers in different instances inthe description and the figures may indicate similar or identical items.

FIG. 1 is an isometric view illustrating a dual-cyclonic spray chamberapparatus in accordance with an example implementation of the presentdisclosure.

FIG. 2A is a top plan view of the dual-cyclonic spray chamber apparatusillustrated in FIG. 1.

FIG. 2B is a bottom plan view of the dual-cyclonic spray chamberapparatus illustrated in FIG. 1.

FIG. 3 is a side elevation view of the dual-cyclonic spray chamberapparatus illustrated in FIG. 1.

FIG. 4 is a cross-sectional side elevation view of the dual-cyclonicspray chamber apparatus illustrated in FIG. 1.

FIG. 5 is a cross-sectional isometric view of the dual-cyclonic spraychamber apparatus illustrated in FIG. 1.

FIG. 6 is an example of output signal intensity over time for a sampletested utilizing a dual-cyclonic spray chamber apparatus for samplepreparation in accordance with an example implementation of the presentdisclosure.

FIG. 7 is a graph illustrating several output signals from a sampletested in a baffled cyclonic spray chamber, such as a second cyclonicspray chamber included with a dual-cyclonic spray chamber apparatus.

FIG. 8 is a graph illustrating several output signals from a sampletested in a non-baffled cyclonic spray chamber, such as a first cyclonicspray chamber included with a dual-cyclonic spray chamber apparatus.

FIG. 9 is a graph illustrating several output signals from a sampletested in a dual-cyclonic spray chamber apparatus in accordance with anexample implementation of the present disclosure.

FIG. 10 is a detection limit comparison chart illustrating a comparisonof furnace element detection limits for a baffled cyclonic spray chamberand a dual-cyclonic spray chamber.

FIG. 11 is a cross-sectional side elevation view of a dicyclonic spraychamber in accordance with example implementations of the presentdisclosure.

FIG. 12 is a cross-sectional side elevation view of a stable sampleintroduction dual spray chamber in accordance with exampleimplementations of the present disclosure.

DETAILED DESCRIPTION Overview

When a sample is introduced to plasma in ICP spectrometry, the hightemperature causes sample atoms to become ionized or emit light.Measuring the spectra of the emitted mass or light allows for thedetermination of the elemental composition of the sample. Sampleanalysis systems may employ a sample introduction system forconditioning a sample prior to introduction into the analyticalequipment. For example, a sample introduction system may withdraw analiquot of a liquid sample from a sample container and transport thealiquot to a nebulizer that converts the aliquot into a polydisperseaerosol suitable for ionization in plasma by the ICP spectrometryinstrumentation. Such conversion may take place in a spray chamber priorto introduction to the plasma. The nebulized sample may include adistribution of large and small aerosol particles. The large aerosolparticles may inhibit signal stability and intensity of the nebulizedsample when analyzed. The spray chamber can be configured to remove thelarger aerosol particles to improve signal stability and intensity ofthe nebulized sample.

One particular spray chamber design is known as a cyclonic spraychamber, which causes the nebulized sample to swirl within the chamber.The larger particles collide with the walls of the chamber and aredrained from the chamber, whereas the smaller particles are expelledfrom the chamber through an outlet, typically located at a vertical endof the chamber. The cyclonic spray chamber may be modified to include abaffle that serves as an additional region of impact for the largerparticles. However, one problem with a baffled cyclonic spray chamber isthat signals from the analyzed sample may be lower than in a non-baffledspray chamber. This may be due to the nebulized sample being introducedin close proximity to the baffle, which may cause smaller aerosolparticles to impact the baffle. Further, a non-baffled cyclonic spraychamber may provide less short term stability than a baffled cyclonicspray chamber, and may lead to a build-up of liquid in the ICP torchinjector, which can reduce signal quality as well as extinguish the ICPplasma.

Accordingly, the present disclosure is directed to a dual spray chamberapparatus that can provide separation of large aerosol particles fromsmaller aerosol particles using two or more spray chambers. The dualspray chamber apparatus can provide short-term stability by mixing usingtwo or more spray chambers, and long-term plasma stability by preventingthe formation of droplets in a torch injector base. The dual spraychamber apparatus includes a first cyclonic spray chamber having aninput port for receiving an aerosol to be conditioned in the interior ofthe first chamber and a second spray chamber coupled with the firstcyclonic spray chamber (e.g., via a linking chamber). The first cyclonicspray chamber may include a baffle disposed in the interior of the firstchamber. The second spray chamber can be implemented as a cyclonic spraychamber, or another type of spray chamber, and may include a baffledisposed in the interior of the second chamber and coupled with anoutput port for supplying a portion of the conditioned aerosol from thefirst chamber via, for example, an ICP torch injector. Inimplementations, the input port of the first cyclonic spray chamber maybe generally orthogonal to the output port of the second spray chamber.In other implementations, the input port of the first cyclonic spraychamber may be generally parallel to the output port of the second spraychamber. In the following discussion, example implementations of dualspray chambers are described.

Example Implementations

FIGS. 1 through 5, 11, and 12 illustrate dual spray chamber apparatus inaccordance with example implementations of the present disclosure. Asshown, a dual spray chamber apparatus 100 includes a first cyclonicspray chamber 102 coupled with a second spray chamber 104. Inimplementations, the second spray chamber 104 can be a cyclonic spraychamber (e.g., as illustrated in FIGS. 1 through 5 and 11). The firstcyclonic spray chamber 102 defines a chamber interior 108, and mayinclude an input port 106, a drain port 110, and an output port 112. Theinput port 106 can be configured to couple with, for instance, anebulizer in order to accept an aerosol produced from the nebulizer. Forexample, the input port 106 can include a threaded connector,quick-connect type coupler hardware, and so forth.

The first cyclonic spray chamber 102 is configured to condition theaerosol by separating relatively large aerosol particles from smalleraerosol particles by allowing the larger aerosol particles to impactwith the walls of the chamber interior 108. In particular, the inputport 106 is configured to receive an aerosol to be conditioned in thechamber interior 108 to produce a first conditioned portion of theaerosol (e.g., the smaller aerosol particles) and a second portion ofthe aerosol (e.g., the larger aerosol particles). With reference to FIG.12, first cyclonic spray chamber 102 can be a baffled cyclonic spraychamber. For example, a baffle 128 may be at least partially disposedwithin chamber interior 108 and coupled with output port 112, so thatbaffle 128 and output port 112 form a continuous path through which thefirst conditioned portion of the aerosol may pass. The second portion ofthe aerosol may be removed from the chamber interior 108 via drain port110. The output port 112 is configured to pass the first conditionedportion of the aerosol from the chamber interior 108 to the second spraychamber 104. The drain port 110 facilitates removal of the secondportion of the aerosol from the chamber interior 108. For instance, thedrain port 110 can remove larger aerosol particles to reduce thebuild-up of aerosol particles within the dual spray chamber apparatus100. Thus, the dual spray chamber apparatus 100 may prevent fluid fromaccumulating within an analytic system, which may include an ICP torchsusceptible to error, extinguishing, and so forth, by excess fluidwithin the system.

The second spray chamber 104 may be coupled with the output port 112 ofthe first cyclonic spray chamber 102 via a linking chamber 114 (e.g., asillustrated in FIGS. 1 through 5 and 11). The second spray chamber 104may not necessarily have a linking chamber 114. For example, the secondspray chamber 104 may be directly coupled with the first cyclonic spraychamber 102 (e.g., as illustrated in FIG. 12). The second spray chamber104 may include a second chamber interior 116, a baffle 118, and anoutput port 120. In some configurations, the second spray chamber 104may not include a baffle. In an example implementation shown in FIG. 12,the second spray chamber 104 may include a generally cylindrical tubedisposed within the second spray chamber 104, such as a guide 130, orthe like (e.g., as illustrated in FIG. 12). The guide 130 may be taperedproximate to the output port 112. The second chamber interior 116 isconfigured to receive the first conditioned portion of the aerosol fromthe output port 112. For instance, the aerosol may swirl within thechamber interior 108, such as in a substantially circular path, in orderto be conditioned. The first conditioned portion may then exit the firstcyclonic spray chamber 102 and pass to the second chamber interior 116via the output port 112. The first conditioned portion may then swirlwithin the second chamber interior 116, so as to be further conditionedin the second spray chamber 104. This dual action may result in thestabilization of a resultant signal (while maintaining signal intensity)from the analysis of the portion of the aerosol exiting the dual spraychamber apparatus 100 via the output port 120.

Referring now to FIGS. 4, 5, and 11, the second spray chamber 104 may bea baffled cyclonic spray chamber. In a particular implementation, thebaffle 118 is at least partially disposed within the chamber interior118 and is coupled with the output port 120, so that the baffle 118 andthe output port 120 form a continuous path through which at least afirst further conditioned portion of the first conditioned portion ofthe aerosol may pass. For example, the baffle 118 may define an interiorportion 122 (e.g., a substantially cylindrical portion) configured toreceive at least a portion of the first conditioned portion of theaerosol for expelling the portion of the first conditioned portion fromthe second chamber interior 116 via the output port 120.

The dual spray chamber apparatus 100 may be configured so that thevolume defined by the first chamber interior 108 is greater than thevolume defined by the second chamber interior 116. When the secondportion of the aerosol is drained from the first cyclonic spray chamber102 (e.g., via the drain port 110), the first conditioned portion of theaerosol may occupy less volume when passed to the second spray chamber104 for further conditioning. By providing a second chamber interior 116having a smaller volume than that of the chamber interior 108, the dualspray chamber apparatus 100 may have a reduced dead (unused) volume whencompared to a configuration having equal volumes for the chamberinterior 108 and the second chamber interior 116. A reduced dead volumemay require less time for a sample signal to stabilize during analysiswith analytic instrumentation. FIG. 6 illustrates an example of outputsignal intensity over time for a sample tested utilizing a dual spraychamber apparatus for sample preparation. The sample was analyzed overan approximately sixteen (16) hour period utilizing an ICP-AES. Theanalysis detected amounts of yttrium (Y), manganese (Mn), arsenic (As),and selenium (Se) in the sample, with the intensities detected as shownin FIG. 6. The stability of the signal of each of the four detectedspecies can be seen with respect to the Relative Standard Deviation(RSD), which ranges from 2.02% (for manganese) to 2.39% (for selenium)in FIG. 6. In other implementations, the volume defined by the firstchamber interior 108 may be equal to or less than the volume defined bythe second chamber interior 116.

As shown in FIGS. 1 through 5, the input port 106 may be positionedgenerally orthogonally to the output port 120. In one particularimplementation, the second spray chamber 104 can be offset with respectto the output port 112, such that the first conditioned portion of theaerosol flowing from the output port 112 is directed tangentially withrespect to the walls of the second chamber interior 116. The portion ofthe aerosol entering the interior portion 122 of the baffle 118 may thenexit the second spray chamber 104 via the output port 120 in anorientation that is orthogonal to the orientation of the input port 106.Since the baffle 118 is included in the second spray chamber 104, thebaffle 118 is separated from the input port 106, which is configured tocouple with a nebulizer in order to accept an aerosol produced from thenebulizer. The separation between the baffle and the input port 106 inthe dual spray chamber apparatus 100 may alleviate signal lossassociated with aerosol impacting the baffle directly after beingintroduced to a spray chamber (such as when solely using a baffled spraychamber).

The linking chamber 114 of the dual spray chamber apparatus 100 may bedisposed between the first cyclonic spray chamber 102 and the secondspray chamber 104. The output port 112 may be disposed at leastpartially within the linking chamber 114. For instance, the output port112 may be positioned approximately concentrically within the linkingchamber 114 and may taper within the linking chamber 114, forming adrain portion 124 within the annular space between the output port 112and the linking chamber 114. The linking chamber 114 may include a drainport 126 coupled with the drain portion 124 (e.g., as illustrated inFIGS. 4, 5, and 11). The drain port 126 may also be included at the baseof the second spray chamber 104 (e.g., as illustrated in FIG. 12). Thedrain port 126 may be configured to pass aerosol particles that wereremoved from the conditioning of the first conditioned aerosol portionin the second spray chamber 104. For example, larger aerosol particlesin the first conditioned aerosol portion may impact with the walls ofthe second chamber interior 116 and/or the baffle 118 and/or the guide130, causing the larger particles to enter into the drain portion 124(in some instances), and exit the dual spray chamber apparatus 100 viathe drain port 126.

Referring now to FIG. 10, a detection limit comparison was performed tocompare furnace element detection limits for a baffled cyclonic spraychamber and a dual spray chamber. The analysis detected amounts ofarsenic (As), lead (Pb), selenium (Se), and thallium (Tl) in samples,with the detection limits as shown in FIG. 10. Detection limits can beseen for the baffled cyclonic spray chamber as compared to detectionlimits for the dual spray chamber. It can be seen that for these twoparticular configurations, the dual spray chamber provided a lowerdetection limit threshold for the samples.

It should be noted that while the dual spray chamber apparatus has beendescribed in the accompanying figures as including two spray chambers,more than two spray chambers may be provided in accordance with thepresent disclosure, such as three spray chambers, four spray chambers,and so forth. For example, in some implementations, a dual spray chamberapparatus may include a third spray chamber (which may be a cyclonicspray chamber or another type of spray chamber) for receiving the firstfurther conditioned portion of the first conditioned portion of theaerosol, and expelling a still further conditioned portion of the firstconditioned portion via another output port included with the thirdspray chamber. The third spray chamber may also be connected to a fourthspray chamber, and so forth. Further, the volume of the interior of eachsuccessive spray chamber may be reduced from the volume of the previousspray chamber (e.g., as previously described). Additionally, the volumeof each successive spray chamber may be equal to or less than the volumeof a preceding spray chamber.

CONCLUSION

Although the subject matter has been described in language specific tostructural features and/or process operations, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A dual spray chamber apparatus comprising: afirst cyclonic spray chamber for receiving an aerosol and conditioningthe aerosol to separate a first conditioned portion of the aerosol froma second portion of the aerosol; a second spray chamber coupled with thefirst cyclonic spray chamber, the second spray chamber for receiving thefirst conditioned portion of the aerosol and further conditioning thefirst conditioned portion of the aerosol to separate a first furtherconditioned portion of the first conditioned portion of the aerosol froma second conditioned portion of the first conditioned portion of theaerosol; and a linking chamber for coupling the first cyclonic spraychamber to the second spray chamber, wherein the linking chambercomprises a taper and forms an annular drain portion for removing thesecond conditioned portion of the first conditioned portion of theaerosol from the second spray chamber.
 2. The dual spray chamberapparatus as recited in claim 1, further comprising a baffle at leastpartially disposed within the first cyclonic spray chamber, the baffledefining an interior portion for receiving the aerosol.
 3. The dualspray chamber apparatus as recited in claim 1, further comprising atleast one of a baffle or a guide at least partially disposed within thesecond chamber interior, the at least one of the baffle or the guidedefining an interior portion for receiving the first further conditionedportion of the first conditioned portion of the aerosol.
 4. The dualspray chamber apparatus as recited in claim 1, wherein the firstcyclonic spray chamber defines a first chamber interior, the firstcyclonic spray chamber comprising an input port in fluid communicationwith the first chamber interior for receiving the aerosol to beconditioned by the first cyclonic spray chamber and a drain port influid communication with the first chamber interior for removing thesecond portion of the aerosol from the first cyclonic spray chamber, andwherein the second spray chamber defines a second chamber interior, thesecond spray chamber comprising an output port for expelling the firstfurther conditioned portion of the first conditioned portion of theaerosol from the second chamber interior.
 5. The dual spray chamberapparatus as recited in claim 4, wherein the input port is oriented atleast one of substantially orthogonally or substantially parallel to theoutput port for expelling the first further conditioned portion of thefirst conditioned portion of the aerosol at least one of substantiallyorthogonally or substantially parallel to the aerosol received at thefirst cyclonic spray chamber.
 6. The dual spray chamber apparatus asrecited in claim 4, wherein a first volume defined by the first chamberinterior is greater than a second volume defined by the second chamberinterior.
 7. The dual spray chamber apparatus as recited in claim 4,wherein the second spray chamber is oriented for directing the firstconditioned portion of the aerosol at least substantially tangentiallyto the second chamber interior.
 8. A dual spray chamber apparatuscomprising: a first cyclonic spray chamber for receiving an aerosol andconditioning the aerosol to separate a first conditioned portion of theaerosol from a second portion of the aerosol, the first cyclonic spraychamber defining a first chamber interior, the first cyclonic spraychamber comprising an input port in fluid communication with the firstchamber interior for receiving the aerosol to be conditioned by thefirst cyclonic spray chamber; a second spray chamber coupled with thefirst cyclonic spray chamber, the second spray chamber for receiving thefirst conditioned portion of the aerosol and further conditioning thefirst conditioned portion of the aerosol to separate a first furtherconditioned portion of the first conditioned portion of the aerosol froma second conditioned portion of the first conditioned portion of theaerosol, the second spray chamber defining a second chamber interior,the second spray chamber comprising an output port for expelling thefirst further conditioned portion of the first conditioned portion ofthe aerosol from the second chamber interior and at least one of abaffle or a guide at least partially disposed within the second chamberinterior, the at least one of the baffle or the guide defining aninterior portion for receiving the first further conditioned portion ofthe first conditioned portion of the aerosol; and a linking chamber forcoupling the first cyclonic spray chamber to the second spray chamber,the linking chamber comprising a taper and forming an annular drainportion for removing the second conditioned portion of the firstconditioned portion of the aerosol from the second spray chamber.
 9. Thedual spray chamber apparatus as recited in claim 8, further comprising abaffle at least partially disposed within the first chamber interior,the baffle defining an interior portion for receiving the aerosol. 10.The dual spray chamber apparatus as recited in claim 8, furthercomprising a drain port in fluid communication with the first chamberinterior for removing the second portion of the aerosol from the firstcyclonic spray chamber.
 11. The dual spray chamber apparatus as recitedin claim 8, wherein the input port is oriented at least one ofsubstantially orthogonally or substantially parallel to the output portfor expelling the first further conditioned portion of the firstconditioned portion of the aerosol at least one of substantiallyorthogonally or substantially parallel to the aerosol received at thefirst cyclonic spray chamber.
 12. The dual spray chamber apparatus asrecited in claim 8, wherein a first volume defined by the first chamberinterior is greater than a second volume defined by the second chamberinterior.
 13. The dual spray chamber apparatus as recited in claim 8,wherein the second spray chamber is oriented for directing the firstconditioned portion of the aerosol at least substantially tangentiallyto the second chamber interior.